make_excutable.t: fix "Cannot execute test_exec.pl" on Win32

Test 'test_exec' instead of 'test_exec.pl'.
Something is broken in the Win32 implementation for '.pl' that we will
have to fix later. For now, just test files without extension.
make_executable.t: [Win32] check any exe, not just .bat

Win32: check that an executable file has been created. Not just '.bat'
as this is too strict and would not allow to change the implementation.
Also check that only one executable script exists.
make_executable.t: test return value (fails on Win32)

Add test of return value of the script.
Win32: test fails because the .bat wrapper does not preserve perl's
return code.
Fix _pl2bat for Win32 errorlevel issues

Refactor the .bat wrapper for Win32.
Now the batch file will forward the perl exit code instead of catching
it and returning 0.
make_executable.t: more exit code tests
pl2bat: better $0 detection in .bat (and avoids -S)

make_executable: improved _pl2bat to use cmd.exe features to detect the
absolute path of the script and pass it as it to perl instead of asking
him to look into PATH.
Merge pull request #1 from dolmen/fix/win32-make_executable

Fixes for make_executable.t and make_executable
Updated Changes
Remove Kwalitee tests
v0.007

          Fixes for make_executable.t and make_executable
Split out Windows/Unix specific parts
Split $ENV{PATHEXT} on $Config{path_sep}
Fixed POD
Updated Changes
v0.008

          Split out Windows and Unix specific parts
          Use $Config{path_sep} in tests
Fixed foobar'ed test
v0.009

          Fixed failing test on Windows
Completely reworked both make_executable's
v0.010

          Fixed make_executable on Windows
Make EU::H easier to embed in inc/